Proportions and Cross Multiply

Solve the proportion:

• 3

• 4

• 9

• 6

Do the ratios form a proportion?

• Yes, they form a proportion.

• No, they do not form a proportion.

Do the ratios form a proportion?

• Yes, they form a proportion.

• No, they do not form a proportion.

Hamburger meat sells for $6 for every 3 pounds. If Alicia buys 10 pounds of hamburger meat, how much will she pay?

• $30

• $20

• $60

• $10

Use the table to write a proportion.

• 2.08/16=d/8

• 8/d=16/2.08

• 2.08/16=8/d

• 2.08/8=d/16

Write a proportion to find how many points a student needs to score on a test in order to get the given percent:
The test is worth 12 points.
The test score is 75%.

• p/12=100/75

• p/100=12/75

• p/12=75/100

• p/75=12/100

Write a proportion to find how many points a student needs to score on a test in order to get the given percent:
The test is worth 60 points.
The test score is 50%.

• p/100=50/60

• p/50=60/100

• p/60=100/50

• p/60=50/100

To solve proportions, you must...

• Multiply the numerators with the numerators

• Cross multiply

• Set equations equal

• Multiply by the denominator